1. Field
The present application relates generally to the operation of wireless communication systems, and more particularly, to an apparatus for providing thermal management for radio frequency devices.
2. Background
Wireless communication devices typically use power amplifiers to transmit radio frequency signals to communicate with other devices. The power amplifiers are typically coupled to an antenna, such as a Planar Inverted F Antenna (PIFA) that is tuned for optimal performance. However, transmitting signals at high power levels can lead to a device experiencing higher than acceptable operating temperatures. Furthermore, the need for wireless devices to be as small as possible in order to be competitive in the market place has resulted in increased power densities, which have further increased operating temperatures. Unfortunately, operating at high temperatures may result in decreased performance or other heat related problems, such as reduced reliability, reduced data rates, or excessively hot touch temperatures.
Several techniques have been used to overcome the problems associated with increased operating temperatures. One technique involves performance throttling (i.e., adjusting data rates, transmit power, etc.) to reduce or limit high temperature exposure to sensitive components. Other techniques that have been used to cool components and dissipate heat include filling air gaps within a device with thermally conductive gap fillers, increasing board area and/or product size, adding vents, and adding fans.
Unfortunately, the above techniques may not be effective in reducing operating temperatures or may result in added material cost, increased product size, or degraded device performance. For example, in a device that utilizes a PIFA, gap fillers are not appropriate since a PIFA typically requires a low loss dielectric, such as air, between the antenna elements and the ground plane for good performance.
Therefore, it would be desirable to have a mechanism that overcomes the problems associated with increased operating temperatures described above thereby allowing high performance compact devices to be built.